$.extend($.fn.datagrid.defaults, {
    onBeforeFetch: function (page) {
    },
    onFetch: function (page, rows) {
    }
});

var scrollview = $.extend({}, $.fn.datagrid.defaults.view, {
    render: function (target, container, frozen) {
        var state = $.data(target, 'datagrid');
        var opts = state.options;
        var rows = this.rows || [];
        if (!rows.length) {
            return;
        }
        var fields = $(target).datagrid('getColumnFields', frozen);

        if (frozen) {
            if (!(opts.rownumbers || (opts.frozenColumns && opts.frozenColumns.length))) {
                return;
            }
        }

        var index = this.index;
        var table = ['<table class="datagrid-btable" cellspacing="0" cellpadding="0" border="0"><tbody>'];
        for (var i = 0; i < rows.length; i++) {
            var css = opts.rowStyler ? opts.rowStyler.call(target, index, rows[i]) : '';
            var classValue = '';
            var styleValue = '';
            if (typeof css == 'string') {
                styleValue = css;
            } else if (css) {
                classValue = css['class'] || '';
                styleValue = css['style'] || '';
            }
            var cls = 'class="datagrid-row ' + (index % 2 && opts.striped ? 'datagrid-row-alt ' : ' ') + classValue + '"';
            var style = styleValue ? 'style="' + styleValue + '"' : '';
            // get the class and style attributes for this row
//			var cls = (index % 2 && opts.striped) ? 'class="datagrid-row datagrid-row-alt"' : 'class="datagrid-row"';
//			var styleValue = opts.rowStyler ? opts.rowStyler.call(target, index, rows[i]) : '';
//			var style = styleValue ? 'style="' + styleValue + '"' : '';
            var rowId = state.rowIdPrefix + '-' + (frozen ? 1 : 2) + '-' + index;
            table.push('<tr id="' + rowId + '" datagrid-row-index="' + index + '" ' + cls + ' ' + style + '>');
            table.push(this.renderRow.call(this, target, fields, frozen, index, rows[i]));
            table.push('</tr>');

            // render the detail row
            if (opts.detailFormatter) {
                table.push('<tr style="display:none;">');
                if (frozen) {
                    table.push('<td colspan=' + (fields.length + 2) + ' style="border-right:0">');
                } else {
                    table.push('<td colspan=' + (fields.length) + '>');
                }
                table.push('<div class="datagrid-row-detail">');
                if (frozen) {
                    table.push('&nbsp;');
                } else {
                    table.push(opts.detailFormatter.call(target, i, rows[i]));
                }
                table.push('</div>');
                table.push('</td>');
                table.push('</tr>');
            }

            index++;
        }
        table.push('</tbody></table>');

        $(container).html(table.join(''));
    },

    renderRow: function (target, fields, frozen, rowIndex, rowData) {
        var opts = $.data(target, 'datagrid').options;

        var cc = [];
        if (frozen && opts.rownumbers) {
            var rownumber = rowIndex + 1;
            if (opts.pagination) {
                rownumber += (opts.pageNumber - 1) * opts.pageSize;
            }
            cc.push('<td class="datagrid-td-rownumber"><div class="datagrid-cell-rownumber">' + rownumber + '</div></td>');
        }
        for (var i = 0; i < fields.length; i++) {
            var field = fields[i];
            var col = $(target).datagrid('getColumnOption', field);
            if (col) {
                var value = rowData[field];	// the field value
                var css = col.styler ? (col.styler(value, rowData, rowIndex) || '') : '';
                var classValue = '';
                var styleValue = '';
                if (typeof css == 'string') {
                    styleValue = css;
                } else if (cc) {
                    classValue = css['class'] || '';
                    styleValue = css['style'] || '';
                }
                var cls = classValue ? 'class="' + classValue + '"' : '';
                var style = col.hidden ? 'style="display:none;' + styleValue + '"' : (styleValue ? 'style="' + styleValue + '"' : '');

                cc.push('<td field="' + field + '" ' + cls + ' ' + style + '>');

                if (col.checkbox) {
                    style = '';
                } else if (col.expander) {
                    style = "text-align:center;height:16px;";
                } else {
                    style = styleValue;
                    if (col.align) {
                        style += ';text-align:' + col.align + ';'
                    }
                    if (!opts.nowrap) {
                        style += ';white-space:normal;height:auto;';
                    } else if (opts.autoRowHeight) {
                        style += ';height:auto;';
                    }
                }

                cc.push('<div style="' + style + '" ');
                if (col.checkbox) {
                    cc.push('class="datagrid-cell-check ');
                } else {
                    cc.push('class="datagrid-cell ' + col.cellClass);
                }
                cc.push('">');

                if (col.checkbox) {
                    cc.push('<input type="checkbox" name="' + field + '" value="' + (value != undefined ? value : '') + '">');
                } else if (col.expander) {
                    //cc.push('<div style="text-align:center;width:16px;height:16px;">');
                    cc.push('<span class="datagrid-row-expander datagrid-row-expand" style="display:inline-block;width:16px;height:16px;cursor:pointer;" />');
                    //cc.push('</div>');
                } else if (col.formatter) {
                    cc.push(col.formatter(value, rowData, rowIndex));
                } else {
                    cc.push(value);
                }

                cc.push('</div>');
                cc.push('</td>');
            }
        }
        return cc.join('');
    },

    bindEvents: function (target) {
        var state = $.data(target, 'datagrid');
        var dc = state.dc;
        var opts = state.options;
        var body = dc.body1.add(dc.body2);
        var clickHandler = ($.data(body[0], 'events') || $._data(body[0], 'events')).click[0].handler;
        body.unbind('click').bind('click', function (e) {
            var tt = $(e.target);
            var tr = tt.closest('tr.datagrid-row');
            if (!tr.length) {
                return
            }
            if (tt.hasClass('datagrid-row-expander')) {
                var rowIndex = parseInt(tr.attr('datagrid-row-index'));
                if (tt.hasClass('datagrid-row-expand')) {
                    $(target).datagrid('expandRow', rowIndex);
                } else {
                    $(target).datagrid('collapseRow', rowIndex);
                }
                $(target).datagrid('fixRowHeight');

            } else {
                clickHandler(e);
            }
            e.stopPropagation();
        });
    },

    onBeforeRender: function (target) {
        var state = $.data(target, 'datagrid');
        var opts = state.options;
        var dc = state.dc;
        var view = this;

        state.data.firstRows = state.data.rows;

        opts.finder = $.extend({}, $.fn.datagrid.defaults.finder, {
            getRow: function (t, p) {
                var index = (typeof p == 'object') ? p.attr('datagrid-row-index') : p;
                var row = $.data(t, 'datagrid').data.rows[index];
                if (!row) {
                    var v = $(t).datagrid('options').view;
                    row = v.rows[index - v.index];
                }
                return row;
            }
        });

        dc.body1.add(dc.body2).empty();
        this.rows = undefined;	// the rows to be rendered
        this.r1 = this.r2 = [];	// the first part and last part of rows

        init();
        createHeaderExpander();

        function init() {
            // erase the onLoadSuccess event, make sure it can't be triggered
            state.onLoadSuccess = opts.onLoadSuccess;
            opts.onLoadSuccess = function () {
            };
            setTimeout(function () {
                dc.body2.unbind('.datagrid').bind('scroll.datagrid', function (e) {
                    if (state.onLoadSuccess) {
                        opts.onLoadSuccess = state.onLoadSuccess;	// restore the onLoadSuccess event
                        state.onLoadSuccess = undefined;
                    }
                    if (view.scrollTimer) {
                        clearTimeout(view.scrollTimer);
                    }
                    view.scrollTimer = setTimeout(function () {
                        scrolling.call(view);
                    }, 50);
                });
                dc.body2.triggerHandler('scroll.datagrid');
            }, 0);
        }

        function scrolling() {
            if (dc.body2.is(':empty')) {
                reload.call(this);
            } else {
                var firstTr = opts.finder.getTr(target, this.index, 'body', 2);
                var lastTr = opts.finder.getTr(target, 0, 'last', 2);
                var headerHeight = dc.view2.children('div.datagrid-header').outerHeight();
                var top = firstTr.position().top - headerHeight;
                var bottom = lastTr.position().top + lastTr.outerHeight() - headerHeight;

                if (top > dc.body2.height() || bottom < 0) {
                    reload.call(this);
                } else if (top > 0) {
                    var page = Math.floor(this.index / opts.pageSize);
                    this.getRows.call(this, target, page, function (rows) {
                        this.r2 = this.r1;
                        this.r1 = rows;
                        this.index = (page - 1) * opts.pageSize;
                        this.rows = this.r1.concat(this.r2);
                        this.populate.call(this, target);
                    });
                } else if (bottom < dc.body2.height()) {
                    var page = Math.floor(this.index / opts.pageSize) + 2;
                    if (this.r2.length) {
                        page++;
                    }
                    this.getRows.call(this, target, page, function (rows) {
                        if (!this.r2.length) {
                            this.r2 = rows;
                        } else {
                            this.r1 = this.r2;
                            this.r2 = rows;
                            this.index += opts.pageSize;
                        }
                        this.rows = this.r1.concat(this.r2);
                        this.populate.call(this, target);
                    });
                }
            }

            function reload() {
                var top = $(dc.body2).scrollTop();
                var index = Math.floor(top / 25);
                var page = Math.floor(index / opts.pageSize) + 1;

                this.getRows.call(this, target, page, function (rows) {
                    this.index = (page - 1) * opts.pageSize;
                    this.rows = rows;
                    this.r1 = rows;
                    this.r2 = [];
                    this.populate.call(this, target);
                    dc.body2.triggerHandler('scroll.datagrid');
                });
            }
        }

        function createHeaderExpander() {
            if (!opts.detailFormatter) {
                return
            }

            var t = $(target);
            var hasExpander = false;
            var fields = t.datagrid('getColumnFields', true).concat(t.datagrid('getColumnFields'));
            for (var i = 0; i < fields.length; i++) {
                var col = t.datagrid('getColumnOption', fields[i]);
                if (col.expander) {
                    hasExpander = true;
                    break;
                }
            }
            if (!hasExpander) {
                if (opts.frozenColumns && opts.frozenColumns.length) {
                    opts.frozenColumns[0].splice(0, 0, {
                        field: '_expander',
                        expander: true,
                        width: 24,
                        resizable: false,
                        fixed: true
                    });
                } else {
                    opts.frozenColumns = [[{
                        field: '_expander',
                        expander: true,
                        width: 24,
                        resizable: false,
                        fixed: true
                    }]];
                }

                var t = dc.view1.children('div.datagrid-header').find('table');
                var td = $('<td rowspan="' + opts.frozenColumns.length + '"><div class="datagrid-header-expander" style="width:24px;"></div></td>');
                if ($('tr', t).length == 0) {
                    td.wrap('<tr></tr>').parent().appendTo($('tbody', t));
                } else if (opts.rownumbers) {
                    td.insertAfter(t.find('td:has(div.datagrid-header-rownumber)'));
                } else {
                    td.prependTo(t.find('tr:first'));
                }
            }

            setTimeout(function () {
                view.bindEvents(target);
            }, 0);
        }
    },

    onAfterRender: function (target) {
        $.fn.datagrid.defaults.view.onAfterRender.call(this, target);
        var dc = $.data(target, 'datagrid').dc;
        var footer = dc.footer1.add(dc.footer2);
        footer.find('span.datagrid-row-expander').css('visibility', 'hidden');
    },

    getRows: function (target, page, callback) {
        var state = $.data(target, 'datagrid');
        var opts = state.options;
        var index = (page - 1) * opts.pageSize;

        if (opts.onBeforeFetch.call(target, page) == false) {
            return
        }

        var rows = state.data.firstRows.slice(index, index + opts.pageSize);
        if (rows.length) {
            opts.onFetch.call(target, page, rows);
            callback.call(this, rows);
        } else {
            var param = $.extend({}, opts.queryParams, {
                page: page,
                rows: opts.pageSize
            });
            if (opts.sortName) {
                $.extend(param, {
                    sort: opts.sortName,
                    order: opts.sortOrder
                });
            }
            if (opts.onBeforeLoad.call(target, param) == false) return;

            $(target).datagrid('loading');
            var result = opts.loader.call(target, param, function (data) {
                $(target).datagrid('loaded');
                var data = opts.loadFilter.call(target, data);
                opts.onFetch.call(target, page, data.rows);
                if (data.rows && data.rows.length) {
                    callback.call(opts.view, data.rows);
                } else {
                    opts.onLoadSuccess.call(target, data);
                }
            }, function () {
                $(target).datagrid('loaded');
                opts.onLoadError.apply(target, arguments);
            });
            if (result == false) {
                $(target).datagrid('loaded');
                if (!state.data.firstRows.length) {
                    opts.onFetch.call(target, page, state.data.firstRows);
                    opts.onLoadSuccess.call(target, state.data);
                }
            }
        }
    },

    populate: function (target) {
        var state = $.data(target, 'datagrid');
        var opts = state.options;
        var dc = state.dc;
        var rowHeight = 25;

        if (this.rows.length) {
            opts.view.render.call(opts.view, target, dc.body2, false);
            opts.view.render.call(opts.view, target, dc.body1, true);
//			dc.body1.add(dc.body2).children('table.datagrid-btable').css({
//				paddingTop: this.index*rowHeight,
//				paddingBottom: state.data.total*rowHeight - this.rows.length*rowHeight - this.index*rowHeight
//			});
            dc.body1.add(dc.body2).children('table.datagrid-btable').css({
                marginTop: this.index * rowHeight,
                marginBottom: state.data.total * rowHeight - this.rows.length * rowHeight - this.index * rowHeight
            });

            var r = [];
            for (var i = 0; i < this.index; i++) {
                r.push({});
            }
            state.data.rows = r.concat(this.rows);

            opts.onLoadSuccess.call(target, {
                total: state.data.total,
                rows: this.rows
            });
        }
    }
});

$.extend($.fn.datagrid.methods, {
    fixDetailRowHeight: function (jq, index) {
        return jq.each(function () {
            var opts = $.data(this, 'datagrid').options;
            var dc = $.data(this, 'datagrid').dc;
            var tr1 = opts.finder.getTr(this, index, 'body', 1).next();
            var tr2 = opts.finder.getTr(this, index, 'body', 2).next();
            // fix the detail row height
            if (tr2.is(':visible')) {
                tr1.css('height', '');
                tr2.css('height', '');
                var height = Math.max(tr1.height(), tr2.height());
                tr1.css('height', height);
                tr2.css('height', height);
            }
            dc.body2.triggerHandler('scroll');
        });
    },
    getExpander: function (jq, index) {	// get row expander object
        var opts = $.data(jq[0], 'datagrid').options;
        return opts.finder.getTr(jq[0], index).find('span.datagrid-row-expander');
    },
    // get row detail container
    getRowDetail: function (jq, index) {
        var opts = $.data(jq[0], 'datagrid').options;
        var tr = opts.finder.getTr(jq[0], index, 'body', 2);
        return tr.next().find('div.datagrid-row-detail');
    },
    expandRow: function (jq, index) {
        return jq.each(function () {
            var opts = $(this).datagrid('options');
            var dc = $.data(this, 'datagrid').dc;
            var expander = $(this).datagrid('getExpander', index);
            if (expander.hasClass('datagrid-row-expand')) {
                expander.removeClass('datagrid-row-expand').addClass('datagrid-row-collapse');
                var tr1 = opts.finder.getTr(this, index, 'body', 1).next();
                var tr2 = opts.finder.getTr(this, index, 'body', 2).next();
                tr1.show();
                tr2.show();
                $(this).datagrid('fixDetailRowHeight', index);
                if (opts.onExpandRow) {
                    var row = $(this).datagrid('getRows')[index];
                    opts.onExpandRow.call(this, index, row);
                }
            }
        });
    },
    collapseRow: function (jq, index) {
        return jq.each(function () {
            var opts = $(this).datagrid('options');
            var dc = $.data(this, 'datagrid').dc;
            var expander = $(this).datagrid('getExpander', index);
            if (expander.hasClass('datagrid-row-collapse')) {
                expander.removeClass('datagrid-row-collapse').addClass('datagrid-row-expand');
                var tr1 = opts.finder.getTr(this, index, 'body', 1).next();
                var tr2 = opts.finder.getTr(this, index, 'body', 2).next();
                tr1.hide();
                tr2.hide();
                dc.body2.triggerHandler('scroll');
                if (opts.onCollapseRow) {
                    var row = $(this).datagrid('getRows')[index];
                    opts.onCollapseRow.call(this, index, row);
                }
            }
        });
    }
});
